A power sharing method for inverters in microgrid based on the virtual power and virtual impedance control

The virtual power method can effectively decouple the inverter output active and reactive power. However, in case of parallel operation the output powers may not be shared very well because of the line impedances mismatching. Therefore, if the system impedances are set to be equal through the virtual impedance loop, then the virtual power loop can successfully share the power. This simply means unifying the parallel inverters equivalent impedance magnitude and angle. Simulation results are presented to prove the effectiveness and feasibility of the proposed control method.